Question

A codeine-containing cough syrup lists codeine sulfate as a major ingredient instead of codeine. The Merck Index gives \(\mathrm{C}_{36} \mathrm{H}_{44} \mathrm{~N}_{2} \mathrm{O}_{10} \mathrm{~S}\) as the formula for codeine sulfate. Describe the composition of codeine sulfate. (See Exercise 143.) Why is codeine sulfate used instead of codeine?

Short answer

Codeine sulfate, with the formula \(\mathrm{C}_{36} \mathrm{H}_{44} \mathrm{N}_{2} \mathrm{O}_{10} \mathrm{S}\), is composed of 36 carbon atoms, 44 hydrogen atoms, 2 nitrogen atoms, 10 oxygen atoms, and 1 sulfur atom. It is used instead of codeine due to its improved water solubility, which makes it easier to formulate into liquid products and allows for better absorption in the body, providing a more effective therapeutic effect.

Step-by-step solution

1. Identify the Elements and Their Atom Counts Present in the Formula

In the formula of codeine sulfate, \(\mathrm{C}_{36} \mathrm{H}_{44} \mathrm{N}_{2} \mathrm{O}_{10} \mathrm{S}\), there are five elements - Carbon (C), Hydrogen (H), Nitrogen (N), Oxygen (O), and Sulfur (S). The subscript numbers are their respective atom counts: -Carbon (C): 36 atoms -Hydrogen (H): 44 atoms -Nitrogen (N): 2 atoms -Oxygen (O): 10 atoms -Sulfur (S): 1 atom

2. Describe the Composition of Codeine Sulfate

Codeine sulfate is a compound composed of the following elements and their atom counts: 1. Carbon (C) with 36 atoms 2. Hydrogen (H) with 44 atoms 3. Nitrogen (N) with 2 atoms 4. Oxygen (O) with 10 atoms 5. Sulfur (S) with 1 atom The chemical formula for codeine sulfate is \(\mathrm{C}_{36} \mathrm{H}_{44} \mathrm{N}_{2} \mathrm{O}_{10} \mathrm{S}\).

3. Explain Why Codeine Sulfate is Used Instead of Codeine

Codeine sulfate is used instead of codeine because of several pharmacological factors that influence drug properties, such as solubility, absorption, and stability. As a sulfate salt, codeine sulfate has improved water solubility compared to codeine, which makes it easier to formulate into liquid products such as cough syrup. Additionally, this enhanced solubility can lead to better absorption of the active compound in the body, ultimately providing a more effective therapeutic effect.

Key concepts

Chemical Formula of Codeine Sulfate

The chemical formula of a compound is a symbolic representation of its elemental constituents and their respective quantities. In the case of codeine sulfate, the formula is coded as \( c_{36}H_{44}N_{2}O_{10}S \), which spells out the precise amount of each element present in one molecule of the substance.

• Carbon (C): 36 atoms
• Hydrogen (H): 44 atoms
• Nitrogen (N): 2 atoms
• Oxygen (O): 10 atoms
• Sulfur (S): 1 atom

This formula is critical as it not only allows us to understand the composition of codeine sulfate but also guides pharmacists and chemists in the synthesis and quality control of the drug.

Elements in Codeine Sulfate

The molecular architecture of codeine sulfate is a crystalline structure comprised of five different types of atoms. These elements are the building blocks of the compound, each contributing to its unique properties.

• Carbon is the backbone of the organic framework, providing a skeleton for the compound.
• Hydrogen atoms are bound to carbon and other elements, affecting the compound's polarity and reactivity.
• Nitrogen atoms typically lend basic properties to the compound and are essential for forming the alkaloid structure within codeine.
• Oxygen atoms, present in high numbers, contribute to the ability of the compound to engage in hydrogen bonding, influencing its solubility.
• Sulfur, as part of the sulfate group, is key in improving water solubility and bioavailability of the molecule when dissolved.

These elements, when combined in the described proportions, form the active ingredient in many medications, utilized for its therapeutic effects.

Pharmacological Factors of Drug Formulation

The formulation of a drug like codeine sulfate considers various pharmacological factors that determine its efficacy and safety. One such parameter is solubility, which is crucial for the drug's absorption into the bloodstream. Codeine sulfate's enhanced water solubility, as compared to pure codeine, makes it more suitable for liquid formulations such as cough syrups.
Moreover, other factors impacting drug design include stability under various conditions, absorption rate, distribution throughout the body, metabolism, and excretion. These factors are meticulously balanced to ensure that the drug has the intended therapeutic effect without causing unwanted side effects.

Improved Absorption and Bioavailability

By converting codeine into its sulfate salt, the medication not only dissolves better in liquids but also displays improved bioavailability. This implies that a greater portion of the drug reaches the systemic circulation, thereby maximizing its therapeutic potential. Thus, the pharmacological benefits of codeine are heightened through its sulfate derivative, justifying its common use over the base form of codeine in medical preparations.